SET @start_value = @@global.read_only;
SELECT @start_value;
@start_value
OFF
'#--------------------FN_DYNVARS_139_01------------------------#'
SET @@global.read_only = 1;
SET @@global.read_only = DEFAULT;
SELECT @@global.read_only;
@@global.read_only
OFF
'#---------------------FN_DYNVARS_139_02-------------------------#'
SET @@global.read_only = @start_value;
SELECT @@global.read_only = 0;
@@global.read_only = 0
1
Warnings:
Warning	1292	Truncated incorrect DOUBLE value: 'OFF'
'#--------------------FN_DYNVARS_139_03------------------------#'
SET @@global.read_only = 0;
SELECT @@global.read_only;
@@global.read_only
OFF
SET @@global.read_only = 1;
SELECT @@global.read_only;
@@global.read_only
ON
SET @@global.read_only = TRUE;
SELECT @@global.read_only;
@@global.read_only
ON
SET @@global.read_only = FALSE;
SELECT @@global.read_only;
@@global.read_only
OFF
SET @@global.read_only = ON;
SELECT @@global.read_only;
@@global.read_only
ON
SET @@global.read_only = OFF;
SELECT @@global.read_only;
@@global.read_only
OFF
'#--------------------FN_DYNVARS_139_04-------------------------#'
SET @@global.read_only = -1;
ERROR 42000: Variable 'read_only' can't be set to the value of '-1'
SELECT @@global.read_only;
@@global.read_only
OFF
SET @@global.read_only = 4294967296;
ERROR 42000: Variable 'read_only' can't be set to the value of '4294967296'
SELECT @@global.read_only;
@@global.read_only
OFF
SET @@global.read_only = 10240022115;
ERROR 42000: Variable 'read_only' can't be set to the value of '10240022115'
SELECT @@global.read_only;
@@global.read_only
OFF
SET @@global.read_only = 10000.01;
ERROR 42000: Incorrect argument type to variable 'read_only'
SELECT @@global.read_only;
@@global.read_only
OFF
SET @@global.read_only = -1024;
ERROR 42000: Variable 'read_only' can't be set to the value of '-1024'
SELECT @@global.read_only;
@@global.read_only
OFF
SET @@global.read_only = 42949672950;
ERROR 42000: Variable 'read_only' can't be set to the value of '42949672950'
SELECT @@global.read_only;
@@global.read_only
OFF
SET @@global.read_only = 'test';
ERROR 42000: Variable 'read_only' can't be set to the value of 'test'
SELECT @@global.read_only;
@@global.read_only
OFF
'#-------------------FN_DYNVARS_139_05----------------------------#'
SET @@session.read_only = 0;
ERROR HY000: Variable 'read_only' is a GLOBAL variable and should be set with SET GLOBAL
SELECT @@read_only;
@@read_only
OFF
'#----------------------FN_DYNVARS_139_06------------------------#'
SELECT @@global.read_only = VARIABLE_VALUE 
FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 
WHERE VARIABLE_NAME='read_only';
@@global.read_only = VARIABLE_VALUE
1
SELECT @@global.read_only = VARIABLE_VALUE
FROM INFORMATION_SCHEMA.SESSION_VARIABLES 
WHERE VARIABLE_NAME='read_only';
@@global.read_only = VARIABLE_VALUE
1
'#---------------------FN_DYNVARS_139_07----------------------#'
SET @@global.read_only = 1;
SELECT @@read_only = @@global.read_only;
@@read_only = @@global.read_only
1
'#---------------------FN_DYNVARS_139_08----------------------#'
SET read_only = 1;
ERROR HY000: Variable 'read_only' is a GLOBAL variable and should be set with SET GLOBAL
SELECT @@read_only;
@@read_only
ON
SELECT local.read_only;
ERROR 42S02: Unknown table 'local' in SELECT
SELECT global.read_only;
ERROR 42S02: Unknown table 'global' in SELECT
SELECT read_only = @@session.read_only;
ERROR 42S22: Unknown column 'read_only' in 'SELECT'
SET @@global.read_only = @start_value;
SELECT @@global.read_only;
@@global.read_only
OFF